Unless something has been changed (which I can't imagine), there should be a Language option under Settings. German should be available for selection there.

If the option is not there, Digitec may be able to help (so it's best to check on site).

I would also be interested, the language German is not available, only others are listed.
How do I get to German?

My device, 2017, can speak German right from the start. And you can change the menu language in the menu.